Download Speed Fluctuates: Why Is That So?

Here’s why your download speed fluctuates:

If you are using an Ethernet connection, it might be your hardware. It could also be caused by your software, a virus, or network congestion. 

If you are using a Wi-Fi connection, it could be any of the above issues, or something else entirely, such as the number of devices you have connected to your Wi-Fi network.

If you want to learn all about why your download speed fluctuates and how to fix it, this article is for you.

Let’s jump right in!

Why Does Your Download Speed Fluctuate? (+ How to Fix It)

Why Is Your Ethernet and Wi-Fi Download Speed Fluctuating?

We’ve all been there.

You’re downloading a game or program, and what looked like it would take sixty seconds suddenly slows to a crawl.

You end up looking at a sixty-minute download or more! 

If you’re thinking, “wow, my download speed fluctuates a lot!” your next question might be why?

Is it due to fluctuation in internet speeds, or is it something else?

Should you switch to a wired connection?

Or, if you’re already using an Ethernet cable, should you switch to WiFi? 

These are questions we’ve all tried to troubleshoot.

Luckily, you don’t have to go it alone!

If your download speed fluctuates wildly, this article is here to help.

Below you’ll find the many possible causes for fluctuating download speed and give you tips on how to fix it.

Let’s dive right in:

Why Is Your Download Speed Fluctuating?

When your internet download speed fluctuates wildly, it’s hard to know where to start. There are several possible causes.

Impatient employee watching his wrist watch in the office.

But before we go too far into troubleshooting territory, let’s make the meaning of fluctuation in internet speed crystal clear:

Internet Fluctuation Meaning 

If you notice your internet speed starts high then drops, we’d call that internet speed fluctuation or download speed fluctuation. 

Technically, internet speed refers to both download and upload speeds. That means it refers to how quickly your computer receives and sends information, respectively. 

Most consumers rely on download speeds more than upload speeds.

We’re more apt to spend time watching movies and listening to music than we are uploading images, as an example.

So, we sometimes use internet speed and download speed interchangeably. 

You can test your internet speed with a simple internet speed or internet fluctuation test.

The test will give you a measure of speed in Mbps (Megabits per Second) for both uploads and downloads. 

When you test your internet speed, you may end up alarmed.

After all, you pay your internet provider to provide internet at a certain speed.

If you’re not getting that, you may be tempted to call your ISP (Internet Service Provider).

But before you get angry at a customer service rep, it’s crucial to understand how internet speed and bandwidth relate. 

Unfortunately, it’s likely that your internet speed won’t match what your internet service provider advertises. That’s because ISP’s advertise their bandwidth, or maximum speed capacity, for their network.

And as you’re about to learn, all sorts of things can keep you from accessing the network’s maximum speed capacity that have very little to do with your ISP. 

What Is Affecting an Fluctuating Internet Connection?

Now that we have that clear, let’s answer the original question. There are a few reasons why your download speed fluctuates.

If you’re using an Ethernet connection, it could be your hardware.

It could also be because of your software, a virus, or network congestion. 

If you’re connecting via Wi-Fi, it could be any of the above issues, or it could have to do with something else entirely, like the number of devices you have connected in your home. 

Let’s break all of that down:

Why Does Your Download Speed Fluctuate with an Ethernet Connection? 

Typically, an Ethernet connection provides more stable download speeds.

If you’re connected directly to the internet via a cable, rather than Wi-Fi, it could be any of the following:


A damaged coaxial cable could be causing all your problems. Make sure you check that first.

Connecting coaxial cable to internet modem.

If your cable is in good repair and firmly connected, check to see if there are any coaxial cable splitters attached. 

A coaxial cable splitter could degrade your internet connection.

Coaxial cable splitters come at different levels of quality and price.

Cheaper, lower quality options will typically degrade your internet connection more than the higher-end versions. 

If you need a splitter, it’s worth it to shell out the extra cash.

If you happen to be using a router with your Ethernet connection, it’s a good idea to check that it is updated and in good repair as well.

Routers can really slow things down if they’re outdated or in need of an update. 

If you don’t have a splitter and your cable and router are on the newer side, hardware probably isn’t the source of your download speed problems. 


If you’re running multiple internet-connected apps simultaneously on your computer, your download speeds will slow accordingly. 

If you go to download a game on Origin, for example, and decide to watch a YouTube video while you wait, you’ll see your Origin download speed fluctuates.  

Download speed fluctuation can happen when applications are running in the background of your computer as well.

Sometimes, you may not even be aware of how many programs are trying to connect to the internet from your device. 

Pressing Control + Alt + Delete opens the task manager on most computers.

The task manager will show you what programs are running and allow you to close the ones you don’t need. 

You should also check your computer’s auto-update or auto-sync settings to ensure it’s not running a backup or trying to install an app update while you’re downloading files. 


If your computer has a virus or malware, downloads may end up moving like molasses in the snow.

Just like with software, viruses can run in the background of your computer, slowing things down without you realizing it. 

Anti-virus software and firewalls can help. That said, you’ll want to make sure whatever site you’re downloading from is accepted by your anti-virus software and any firewalls you put in place.

Otherwise, it could attempt to block the download, which won’t just slow you down; it’ll stop you altogether!


Have you ever noticed that your download speed suddenly slows down right around the time your neighbor gets home from work? It might not be your imagination. 

Though we pay for certain internet speeds, in reality, we all share a network with everyone else in our geographic vicinity.

Internet speeds can slow when everyone tries to connect at once. 

Many people note slower internet download speeds right at six o’clock when people are getting home from work.

The same is true at around three pm when children get home from school and at about nine am when people are starting their workday. 

It could also be that your ISP has oversold its capacity, especially at peak times. But that’s, unfortunately, unsolvable from your end.

You can call your ISP and let them know your internet speeds are fluctuating, though. 

It’s possible that there’s an issue with their hardware, like the cable that connects your house to their network.

In that case, it’s fixable, and your internet speed stability should improve as soon as the repairs are done.  

Why Is Your Wi-Fi Strength Fluctuating? 

If you notice your Wi-Fi download speed fluctuates, it could be your software, a virus, or internet congestion, like we talked about above.

However, it could also be your Wi-Fi-specific hardware, your Wi-Fi signal, or the number of devices in your home that’s causing the problem. 


Wi-Fi network hardware can have a significant effect on your download speeds.

If you’re using an out-of-date router or modem, your download speed could plummet even if it starts out looking strong. 

Sometimes, even a newer Wi-Fi router can end up bogged down and slow. If that happens, a reboot is in order.

Rebooting a router is very simple and usually involves pushing a button on the side of the device. 

Man pressing the power button on the WiFi router.

If your modem is separate from your router, you may need to reboot that too.

Doing so should help your download speed overall, and may help prevent significant speed fluctuations in the future. 

Wi-Fi Signal 

Your internet could be completely fine, and the problem with fluctuating download speeds could be with your Wi-Fi signal.

Wi-Fi connects you to the internet, so you need to connect to it before you’re downloading anything wirelessly. 

If you’re asking, “why does my Wi-Fi signal strength fluctuate?” The answer isn’t straightforward. 

It could be that you have something interfering with your Wi-Fi signal.

If your router is on a metal desk or next to a metal wall, you might want to move it. Metal can obscure the signal. 

It’s also possible that another household appliance is interfering, such as a microwave or an old cordless phone.

Or, if you’re in an older house, it could be the metal supports within the walls that you can’t see. 

Alternatively, you could have a Wi-Fi dead zone.

You’ll know if that’s the case because if you move your internet-connected device to a different room that’s the same distance from your router, you’ll see your Wi-Fi signal increase.

A powerline adaptor or Wi-Fi repeater could help with Wi-Fi dead zone issues. 

Number of Connected Devices 

Most homes have more than one device connected to the internet at a time.

You might have your TV, your laptop, and your smartphone all relying on your home’s Wi-Fi at once. 

The more connected devices you have, the more fluctuation you’ll see in download speeds. 

So if you’re thinking, “my Wi-Fi speed varies a lot,” you could try turning off a device or two while you’re downloading games or large files.

Alternatively, you could try upgrading your internet package. 


  • Theresa McDonough

    Tech entrepreneur and founder of Tech Medic, who has become a prominent advocate for the Right to Repair movement. She has testified before the US Federal Trade Commission and been featured on CBS Sunday Morning, helping influence change within the tech industry.

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